This application claims the benefit of Korean Application No. 97-76404, filed Dec. 29, 1997 in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a terminal system having both an asynchronous transfer mode terminal function and an asynchronous transfer modebased asymmetric digital subscriber line terminal function and method therefor.
2. Description of the Related Art
While an asynchronous transfer mode (xe2x80x9cATMxe2x80x9d) terminal generally complies with particular ATM forum standards, an ATM-based-asymmetric digital subscriber line (xe2x80x9cADSLxe2x80x9d) terminal generally complies with ADSL forum standards. The ATM terminal includes physical media, a physical media dependent (xe2x80x9cPMDxe2x80x9d) sublayer, and a transmission conversion (xe2x80x9cTCxe2x80x9d) portion that are different from those of the ATM-based-ADSL terminal, and an ATM cell segmentation and reassembly (xe2x80x9cSARxe2x80x9d) portion that is the same as a SAR portion of the ATM-based-ADSL terminal.
FIG. 1A is a block diagram illustrating a conventional ATM-based-ADSL terminal system. As illustrated in FIG. 1A, the conventional ATM-based-ADSL terminal system includes an ADSL PMD sublayer 100 in which a public switched telephone functions as a transfer medium, an ADSL TC portion 102, and an ATM SAR portion 104.
As illustrated in FIG. 1A, during operation of the conventional ATM-based-ADSL terminal system, the ADSL TC portion 102 receives a cell of serial data through the ADSL PMD sublayer 100. The ADSL TC portion 102 delineates the received cell according to a control signal received through a peripheral component interconnect (xe2x80x9cPCIxe2x80x9d) bus and ATM SAR portion 104, divides the serial data into units of ATM cells, and transfers the ATM cells in parallel using a UTOPIA Rx1 bus. The ATM SAR portion 104 assembles the data received from the ADSL TC portion 102 to generate and output user information.
When a user attempts to transfer data through the ADSL network, the ATM SAR portion 104 transfers the user information to be transmitted to the ADSL TC portion 102. The ADSL TC portion 102 converges the ATM cells transferred in parallel from the ATM SAR portion 104 through a UTOPIA Tx1 bus into an ADSL data frame, and transfers the ADSL data frame according to a transmission clock input from the ADSL PMD sublayer 100.
A conventional ATM terminal system is illustrated in the block diagram of FIG. 1B. The conventional ATM terminal system of FIG. 1B includes an ATM physical media dependent (xe2x80x9cPMDxe2x80x9d) sublayer 106, an ATM TC portion 108, and an ATM SAR portion 110.
Operation of the conventional ATM terminal system of FIG. 1B is similar to the conventional ATM-based ADSL terminal system of FIG. 1A. Namely, the ATM TC portion 108 delineates a cell of serial data received from an ATM network through the ATM PMD sublayer 106, according to control signals received through a PCI bus and the ATM SAR portion 110, divides the serial data into units of ATM cells, and transfers the ATM cells in parallel using a UTOPIA Rx2 bus. The ATM SAR portion 110 assembles the received data into user information and outputs the user information.
When a user attempts to transfer data through the ATM network, the ATM SAR portion 110 divides the user information that is to be transferred into an ATM cell pattern. The ATM TC portion 108 converges the ATM cells that are transferred in parallel through a UTOPIA Tx2 bus into an ATM data frame, and transfers the ATM data frame according to a transmission clock received from the ATM PMD 106.
However, in order to connect the conventional ATM network with the conventional ADSL network through a terminal system, different terminal systems are required for each network.
It is an object of the present invention to provide a terminal system that shares a common portion of an ATM terminal system and an ATM-based-ADSL terminal system, thus having the functions of both, in order to connect the ATM network and the ADSL network through a terminal system.
Additional objects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Accordingly, objects of the invention are achieved by a terminal system that enables a user to selectively connect an asynchronous transfer mode terminal through a corresponding physical media dependent sublayer, or an asymmetric digital subscriber line terminal through a corresponding physical media dependent sublayer. The terminal system includes a transmission conversion portion that connects with the physical media dependent sublayers and converts serial data from the connected physical media dependent sublayer into parallel data. A cell segmentation and reassembly portion assembles the parallel data from the transmission conversion portion, changes the assembled data into user information including user information to be transferred, divides the user information to be transmitted into predetermined data cells, and outputs the predetermined data cells to the transmission conversion portion. The transmission conversion portion converts the predetermined data cells into serial data and transfers the converted serial data to the connected physical media dependent sublayer.
Further objects of the invention are achieved by a terminal system having both an asynchronous transfer mode terminal function and an asynchronous transfer mode-based asymmetric digital subscriber line terminal function, that enables a user to select connection to an asynchronous transfer mode network or an asymmetric digital subscriber line network. The terminal system includes a first transmission conversion portion intrinsic to the asynchronous transfer mode network, and a second transmission conversion portion intrinsic to the asymmetric digital subscriber line. A common transmission conversion portion converts serial data from the first transmission conversion portion and the second transmission conversion portion into parallel data. Data is transferred through the first transmission conversion portion and the common transmission conversion portion when the asynchronous transfer mode network is selected, and data is transferred through the second transmission conversion portion and the common transmission portion when the asymmetric digital subscriber line is selected by the user.
Further objects of the invention are achieved by a terminal system having both an asynchronous transfer mode terminal function and an asynchronous transfer mode-based asymmetric digital subscriber line terminal function, that enables a user to selectively connect an asynchronous transfer mode network or an asymmetric digital subscriber line network. The terminal system includes a first physical media dependent sublayer, corresponding to the asynchronous transfer mode network, to output data cells, and a second physical media dependent sublayer, corresponding to the asymmetric digital subscriber line network, to output data cells. A first transmission conversion portion intrinsic to the asynchronous mode network delineates the data cells output by the first physical media dependent sublayer, and a second transmission conversion portion intrinsic to the asymmetric digital subscriber line network delineates the data cells output by the second physical media dependent sublayer. A selector selects the first transmission conversion portion or the second transmission conversion portion, and a common transmission conversion portion converts serial data from the transmission conversion portion selected by the selector into parallel data. A cell segmentation and reassembly portion assembles the parallel data from the common transmission conversion portion, changes the assembled data to user information that includes user information to be transmitted, divides the user information to be transmitted into predetermined data cells, and outputs the predetermined data cells to the common transmission conversion portion. The common transmission conversion portion converts the predetermined data cells into serial data and outputs the converted serial data to the selector.